<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>判断奇偶性</title>
</head>
<body>
    <script>
        //1.声明变量，输入数据
        var num=Number(prompt('请输入一个数'));
        //2.判断数值奇偶性
        if(num%2==0){
            alert(num+'为偶数');
        }else{
            alert(num+'为奇数')
        }
    </script>
</body>
</html>